fpmd123

Hi, new to forums. I have a '00 LX470 with 150K miles. Every so often, the vehicle will lower without activating the AHC switch. The dash light does not change from N to L, the vehicle will just lower. This may occur right when starting up while vehicle in Park, but also occurs while sitting at a stoplight. The AHC switch also was not activated to High so the vehicle was just resetting to normal at traffic speeds. Has anyone noticed this before? The nearest Lexus dealer is 250 miles away, so I've checked with the local Toyota dealer and they didn't offer much to answer the cause. Any reason to worry?